This invention relates to agents comprising antimicrobially active compounds of the general formula: ##STR2## and R.sub.1, R.sub.2, R.sub.5 and R.sub.6 represent hydrogen (for R.sub.5 and R.sub.6 only), chlorine, bromine or alkyl groups with up to 5 C-atoms, R.sub.3 represents hydrogen, sodium, potassium, magnesium, calcium, barium, tin, zinc, copper, ammonium or substituted ammonium and wherein furthermore, R.sub.1, R.sub.2 and R.sub.4 may be interchangeably positioned in the ortho-position as well as in the para-position, and fungicides which may be used for chemical control of phytopathogenical fungi and bacteria. These compounds are used against mycoses and bacterioses in the culture of grain, fruit, potatoes, vegetables and ornamental plants, and as a preparation and protective in storage for agricultural and horticultural crops, particularly against the inciter of the bacterial nodular-wet rot (Erwinia spp), the nodular-dry rot (Fusarium spp. and Phoma spp.) and the rhizoctonia (Rhizoctonia solani Kuhn) on potato tubers as well as bark diseases in the culture of fruits.
Mycoses and bacterioses of culture plants cause losses of crops and losses of stored harvested goods every year, which are estimated to be more than 20 billion a year. The use of plant protectives has, in addition to cultivation, a decisive significance in the exploitation of the potentially high yield of our cultured plants and for the protection of the stored goods. For many plant diseases, no completely satisfactory or sufficiently economical solutions are known (mixed rot of stored crops, bark diseases in fruit culture and others). That relates particularly to plant protectives against bacterioses, except potato preparation. A worldwide problem is represented by the losses due to rotting of crops during storage periods, particularly potatoes. Literature of this field mentions chemical methods of fighting, which are directed against fungal and bacterial damaging inciters on the potato tubers. The benzimidazoles were among the various active compounds used that were the most effective against nodular-dry rot (Fusarium spp. and Phoma spp.) (Thiabendazol, Fuberidazol, Benomyl, Garbendazim etc.) (DD-WP No. 130,427, DD-WP No. 110,423; DE-AS Nos. 1,209,799 and 1,237,731; DE-OS No. 1,745,784; U.S. Pat. Nos. 3,631,175 and 3,657,443; DD-WP No. 107,204).
Dithiocarbamate was also used against nodular-dry rot. In order to combat rhizoctonia, principally pentachloronitrobenzene, Maneb and Mancozeb were used. In order to successfully combat bacterial nodular-wet rot (Erwinia spp.) at practical conditions, only the antibiotic chloramphenicol can be noted (DD-WP No. 78 423). In order to successfully combat all injurious inciters, it was found advantageous to use a mixture comprising a benzimidazole fungicide and chloramphenicol (DD-WP Nos. 110,423 and 130,427). This mixture forms the basis for the preferred treatment of potato tubers which are intended for subsequent storage.
The use of chloramphenicol, which was after all the first broadband antibiotic and also the first antibiotic that could be prepared synthetically, results in many risks when used as a preparation on stored crops.
WHO (WORLD HEALTH ORGANIZATION) recommends never to use paramedically an antibiotics that are used in human medicine. Therefore it is international custom not to use chloramphenicol for plant protection.
The fact that constant use of chloramphenicol as a plant protectant in agriculture causes seeping into the environment has to be taken very seriously, since it results in a reduction of sensitivity of bacteria. (Rosenthal, and others 1977). A lowered sensitivity is frequently connected to resistance factors (r-plasmids) which may be transferred by conjugation or transduction in bacteria between species, genera, families and even orders and may therefore cause disasterous consequences for remedy (WHO, 1973; RISCHE, 1975).
Antimicrobially effective compounds of the general formula I are novel active materials having the type of composition of known antimicrobially active phenols, whose synthesis may be started from a waste product of herbicide synthesis (4-chloro-2-methylphenol-synthesis) (DD-WP No. 131,746). They are characterized by good antimicrobial properties which permit their recommendation in human and in veterinary medicine. Furthermore, it is known that derivatives of phenol, such as chlorophenol, pentachlorophenol, cresol, chlorocresol, benzylphenol, benzylchlorophenol and thymol are antimicrobially active and may therefore be used as potential combination partners for fungicides for increased effectiveness and widening of the inactivity spectrum. Disadvantages of these compounds are their partially very high phytotoxicity and toxicity for warm-blooded animals, making their use in plant protection impossible.